This invention relates to the recovery of tungsten values from aqueous alkali metal tungstate solutions by liquid-liquid solvent-extraction process. More particularly, the invention relates to the extraction of tungsten values by an organic mixture and subsequent recovery as an ammonium tungstate solution by stripping.
Prior art processes relating to recovery of tungsten include U.S. Pat. Nos. 3,158,438 to Kurtak; 3,256,058 to Burwell; and 3,293,004 to Musgrove et al; South African Pat. No. 684,892 and British patent 1,240,524. U.S. Pat. No. 4,175,109 to Kim relates to a tungsten extraction process.
It is an object of the present invention to provide an improved process for recovery of tungsten values from aqueous alkali metal tungstate solutions.
Other and further objects will become apparent from reading the following description.